{"id":"CVE-2026-27979","aliases":["GHSA-h27x-g6w4-24gq"],"url":"https://o3.security/vulnerability/CVE-2026-27979","summary":"Next.js: Unbounded postponed resume buffering can lead to DoS","details":"Next.js is a React framework for building full-stack web applications. Starting in version 16.0.1 and prior to version 16.1.7, a request containing the `next-resume: 1` header (corresponding with a PPR resume request) would buffer request bodies without consistently enforcing `maxPostponedStateSize` in certain setups. The previous mitigation protected minimal-mode deployments, but equivalent non-minimal deployments remained vulnerable to the same unbounded postponed resume-body buffering behavior. In applications using the App Router with Partial Prerendering capability enabled (via `experimental.ppr` or `cacheComponents`), an attacker could send oversized `next-resume` POST payloads that were buffered without consistent size enforcement in non-minimal deployments, causing excessive memory usage and potential denial of service. This is fixed in version 16.1.7 by enforcing size limits across all postponed-body buffering paths and erroring when limits are exceeded. If upgrading is not immediately possible, block requests containing the `next-resume` header, as this is never valid to be sent from an untrusted client.","published":"2026-03-18T00:13:29.748Z","modified":"2026-08-12T03:51:30.134679880Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"next","fixedVersion":"16.1.7"}],"fix":{"url":"https://github.com/vercel/next.js/commit/c885d4825f800dd1e49ead37274dcd08cdd6f3f1","label":"vercel/next.js@c885d48"},"references":[{"type":"WEB","url":"https://github.com/vercel/next.js/releases/tag/v16.1.7"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27979.json"},{"type":"ADVISORY","url":"https://github.com/vercel/next.js/security/advisories/GHSA-h27x-g6w4-24gq"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-27979"},{"type":"FIX","url":"https://github.com/vercel/next.js/commit/c885d4825f800dd1e49ead37274dcd08cdd6f3f1"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:30.134679880Z"}}